I'm pretty new to micro-controllers so this is my 1st big project... I want to make a simple tremolo with controls for rate. depth and volume. I'm using a digital potentiometer to modulate the guitar signal (which works better than you might expect), the only thing is that the modulation depth is something that can be controlled well in the digital domain. The resolution is only 8 bits so that allows only 3 levels of depth ( + 1 which is flat). Any suggestions how can I do this using an analog circuit?